Graeme McDowell is expecting a battle royale with stablemate Gareth Maybin for the Andalucia Valderrama Masters on Sunday afternoon.

The US Open champion (72) , who trails Martin Kaymer by close to €1m at the top of the Race to Dubai, double bogeyed the 18th to go into the final round tied for the lead with the Ballyclare man (70) on six under par.

“Gareth played lovely today,” McDowell said. “He has really come on as a player over the last few years and he’s very solid, very sharp, great short game, good putter. He doesn’t do a lot wrong so he is going to be a formidable opponent tomorrow.”

It was an erratic performance by McDowell, who should have been at least one under par for the first five holes before a double bogey at the seventh put him on the back foot.

He mixed two birdies with two bogeys in the next five holes as Maybin recovered from bogeys at the first and second with birdies at the third, fourth and ninth to take sole possession of the lead with seven holes to play.

McDowell was struggling with his game but he found a solution and picked up birdies at the 13th, 15th and 17th to go to the last with a two-stroke lead only to throw it away by taking four to get down from greenside sand.

Short-sided in the right greenside trap after over-cutting a six-iron from the middle of the fairway, he feared a lack of sand in the bunker and came up short with his delicate bunker shot, finishing in the deep collar of rough surrounding the green.

Maybin had chipped close for par from the rough on the front right but McDowell miscalculated his fourth, skipped 20 feet past and failed to convert his bogey putt.

It all added up to a one over 72 for the Portrush man as Maybin signed for a one-under par 70, leaving them four clear of Damien McGrane (70) and Miguel Angel Jiménez at the top with Sergio Garcia and Thomas Bjorn five shots back on one under.

As for Kaymer, who needs a top-two finish to become world No 1, the German carded a 70 to share 17th place on three over par. With high winds forecast, he may need a round in the mid-60s and help from those in front to have any chance of denying Lee Westwood the honour of taking over from Tiger Woods as the game’s top ranked player.

While McDowell is only interested in cutting Kaymer’s lead at the top of the money list, he saw on Saturday that Maybin will be no pushover in the final round.

With windy conditions forecast, he knows that he will need to fire on all cylinders for all 18 holes, which wasn’t the case in Saturday’s third round.

“There was a stretch of four or five holes there where I was just all over the place,” he said. “Then I really steadied the ship again - I birdied 13, great chance on 14, birdied 15, up and down on 16 and birdied 17. I am standing in the 18th fairway thinking, this is great, let’s finish the job and I walk off with six.

“It was one of those very careless ways to finish. But there was enough good golf in there to keep me happy. I am in a great position, going into Sunday afternoon with a chance to win a golf tournament. I would have taken that on Thursday.”

“Tied with Gareth going into tomorrow. The weather has spreadeagled the field a little bit. We are well clear of third and fourth and have to do a job tomorrow.”

Maybin, 30, is seeking his maiden win in just his second full season on the European Tour. But at 58th in the Race to Dubai, he knows he can secure his place in the season-ending Dubai World Championship for the second year in succession.

“I had a rough enough start but battled back hard, knuckled down and got a good result out of it,” he said after his third successive sub-par round. “Valderrama can be pretty brutal so to shoot under par is a pretty good result.”

As for his battle with McDowell, he said: “I knew last night that I was playing with him. He is probably one of the hottest players in the world right now and at the top of his form. To go out today and get a result against him is something, I will take a lot from it.

“Tomorrow will be a big battle, a friendly battle. He was unfortunate at the last but I expect him to come out fighting.”

Beaten in a play-off for the South African Open at the start of last season, Maybin finished 53rd in the Race to Dubai in his rookie year but has yet to win.

“I have had a couple of chances over the last few years,” he conceded. “This is one of the most prestigious golf tournaments on one of the most prestigious golf courses. If I could get a victory it would mean a lot.”